SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0e2035bc3db2adb48027861a0f487f3a2c5f5580ad20e6d09be7c107fa3541e6' 
  AND token = '8manIjVjDgwzPbH6TgR6XVy0kp2/UOTkt624wY0xGEI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}